Effects Of Soil PH Value On Occurrence Of Carya Cathayensis Canker Disease

Soil pH plays an important role in plant health and disease resistance.In order to understand the influence of soil pH on the occurrence of Carya cathayensis canker disease,this article analyzed the impact of soil pH and types,different fertilization treatments and weeding methods on the disease index of Carya cathayensis canker disease by investigating hickory forest field plots.Test groups of hickory seedlings with different soil pH values was set up,and the effects of different soil pH values on the occurrence of Carya cathayensis canker disease after infected by B.dothidea were measured.And using high-throughput sequencing to know the effect of different pH values on the microbial diversity of hickory potted soil.The main results are as follows:1.The results of field survey and analysis of hickory forest sample plots showed that the disease index of hickory canker disease with soil pH of 4.50-5.49 was 34.43,which was significantly higher than that of soils with pH of 5.50-6.49 and 6.50-7.49.The disease index of canker disease of lithologic soil’s hickory was 39.04,which was significantly higher than that of yellow soil and red soil.The disease index of hickory canker disease with long-term application of chemical fertilizer was 47.87,which was significantly higher than the application of compound fertilizer and no fertilizer.The disease index of hickory canker disease with long-term application of chemical weeding was 35.03,which was significantly higher than that of no weeding and physical weeding.2.The results of artificial inoculation showed that the lesion diameter and disease index of hickory canker disease with soil pH values of 4.5 and 5.5 were significantly higher than that of soil pH values of6.5 and 7.5.The content of lignin,total phenols,total flavonoids,and anti-disease enzyme activities of hickory with soil pH values of 7.5 and 6.5 were significantly higher than those of soil pH values of 5.5and 4.5 after inoculation with B.dothidea.3.The results of high-throughput sequencing showed that the amount of bacterial OTU,Shannon,Ace,Simpon and Chao index of soil bacteria in the potted soil of hickory seedlings with pH values of7.5 and 6.5 were significantly higher than those of pH values of 5.5 and 4.5.The amount of fungal OTU,Shannon,Ace,Simpon and Chao index of soil fungi in the potted seedlings with pH values of 7.5 and6.5 were significantly lower than those of pH values of 5.5 and 4.5.4.At the phylum level,the abundance of Proteobacteria in the soil of hickory with pH values of7.5 and 6.5 was significantly lower than that pH values of 5.5 and 4.5.the abundance of Bacteroidetes with pH value of 6.5 was significantly higher than that pH values of,5.5 and 4.5.The abundances of soil Mortierellomycota and Chytridiomycota in the soil of hickory with pH values of 7.5 and 6.5 were significantly higher and lower than pH values of 5.5 and 4.5 respectively.5.At the genus level,the dominant genera of soil bacteria in hickory with pH values of 5.5 and 4.5were Phenylobacterium,Opitutus,and Dyella,Gallionell respectively;the dominant genera of soil fungi were Hydnum,Pyricularia,Cladophialophora,Exophiala and Chaetomium,Fibulochlamys,Synchytrium,Pandora respectively.The dominant genera of soil bacteria in hickory with pH values of7.5 and 6.5 were Haliangium,Reyranella,Nitrospira and Caulobacter,Pseudomonas,Hirschia respectively;the dominant genera of soil fungi were Thelephora,Discosia,Myrothecium,Humicola,Olpidium and Conocybe,Hydnoplicata,Arthrobotrys,Phialophora,Mortierella,Fusarium respectively.The research results can provide reference for the sustainable and healthy management of hickory forest and the comprehensive ecological control of hickory canker disease.